I started with something along the lines of an AK-74 brake, but it looked like ass on an AR so it's been bored out and looks great on an AK.
I'm building something like the kies linear comp, but I wanted one a bit shorter and a slightly smaller diameter.
Some day soon I'll have a mill and can do some real nice stuff but till then....
I'm building this just for kicks. I understand that they usually can be bought cheaper than building them(considering time, tooling, etc.).
I'm wondering what the smallest bore diameter should be.
I'd imagine manufacturers of brakes are walking a fine line between what works best by hugging the bullet, and what will cause the fewest problems due to the bullet striking the brake.
They probably also err toward a larger hole just to be safe.
I see alot of suppressors use a .25" hole, but those are alot longer than a MB.
I used a 15/64" (.234") drill. It clears a 5.56 round fine and cleaning rods fall through the bore without contact. That's only around .0055" clearance all the way around.... But the muzzle to end of brake is pretty short.
The reason I went so tight is that I figured the tighter it is, the more gasses will go where I want (even if it is just a tiny fraction of a second worth of help).
Think I'll have an issue? Better play it safe and go to .25"?
I'll have pictures if anyone wants after it comes out of an oil bath curing the cold blue.
EDIT to add pictures....
I cut the threads and spun the brake off-center for the holes to get what you see here...boring stuff.
First it was polished so the media blasting could go onto a nice even surface. Don't know if it helped, but it only took a couple of minutes...
After that, I could tell I wanted the diameter a bit smaller and the face to be countersunk, but otherwise it was the same.
After blasting and a dip in cold blue (with a few hours soaking in oil after to help cure).
Birdcage for size comparison...
I probably should have machined flats onto it, but then the thought hit me that I have a piece of the front left over where I patred it off. I'll just pound some pins in it and use it as a wrench.
And if it doesn't work worth a flip - who cares. It was only a couple of hours work and it was fun. I'll try another soon.
Bump for interest. Also, if anyone out there has a CFD program with which to evaluate an Inventor drawing of a compensator, that would be super.
Also interested. I'm not aware of any CFD programs that aren't licensed for thousands of dollars a year, but I work with computational EM tools, nothing so mechanical as fluids.